Industry standards are periodically updated to reflect new recommendations for petroleum products, such as a standard associated with possible carcinogenic classifications of aromatic extracts. The mutagenicity index (MI) is typically used to define the carcinogenicity of an aromatic extract. Testing a product stream for its MI value to ensure that the MI value is less than a particular value defined in a standard, however, is time consuming and impractical, as aromatic extract would need to be tested for each batch or product. Therefore, it would be advantageous to avoid the time-consuming testing involved in determining the MI value of an aromatic extract.
U.S. Pat. No. 5,034,119 describes a process for establishing a functional relationship between a mutagenicity index and a physical property correlative of hydrocarbon type for the bright stock extract or deasphalted oil to produce non-carcinogenic bright stock extracts and/or deasphalted oils. The functional relationship results in a product having a mutagenicity index of less than 1.0. Process conditions are established so that a product stream achieving the desired physical property level can be produced.